Image Processing with gluas

introduction to pixel molding

Øyvind Kolås


Table of Contents

Preface
1. Digital image representation
Vector images
Coordinate system
Defining shapes
Bitmap images
Sampling
Image compression
File formats and applications
2. The gluas environment
Installing gluas
Windows
In Linux, from source
Using gluas
The lua language
Setting and getting pixel values
Shadow buffer
Samples
A simple program
Gluas reference
Functions
Variables
Gluas compatible software
3. Visual Debugging Aids
Histogram
Chromaticity Diagram
Luminance Profile
4. Point operations
Threshold
Brightness
Contrast
Brightness + Contrast
Invert
Gamma
Levels
Curves
Lookup tables
Excercises
1. Exchange Red and Green
2. Value boost
3. Checkerboard
4. Position dependent contrast
5. Area operations
Sampling area
Edge handling
Convolution Matrix
Smoothing filters
Box blur
Gaussian blur
Speeding up blur by decomposing
Edge preserving
Rank/statistical filters
Median
Unsharp mask
Misc area filters.
Jitter
Excercises
1. Extend the convolve example
2. Adaptive blur
3. Circle
6. Resampling
Affine transformations
Translation
Rotation
Scaling
Other transformations
Perspective transform
Lens correction
Interpolation
Bilinear interpolation
Bicubic interpolation
Decimation
Trilinear interpolation
Excercises
1. Interpolation error visualization
2. Study the assignment
7. Automatic color adjustments
Contrast stretching
Automatic white balance
Grayworld assumption
Component stretching
Automatic spatial algorithms
Local Contrast Enhancement
Excercises
1. Problems with the Local Contrast Enhancement filter
8. Countering artifacts
Static sensor noise
Film grain
CCD sampling noise
Quantification
Interlacing
Line doubling
Linear blend
Temporal resampling
Aliasing
Color casts
A. Assignment, spring 2007
Introduction
Goal
Report
Dataset
Hints

List of Figures

1.1. Coordinate system.
1.2. Vector image
1.3. Raster image
1.4. Sampling grid
1.5. Sample depth
1.6. RGB bands
1.7. Indexed image
1.8. Run-length encoding
1.9. JPEG generation loss
2.1. Screenshot of gluas
2.2. basic gluas program
3.1. histogram
3.2. chromaticity diagram
3.3. luminance profile
4.1. threshold
4.2. brightness
4.3. brightness subtraction
4.4. contrast
4.5. brightness and contrast
4.6. invert
4.7. gamma
4.8. The GIMP's levels tool
4.9. levels
4.10. The GIMP's curves tool
5.1. Sliding window
5.2. Over the edge
5.3. convolve
5.4. blur
5.5. kuwahara
5.6. snn
5.7. median
5.8. jitter
6.1. translation
6.2. rotation
6.3. scaling
6.4. bilinear
6.5. bicubic
6.6. box decimate
7.1. contrast stretching
7.2. grayworld assumption
7.3. component stretching
7.4. lce

List of Tables

1.1. Common/encountered raster dimensions
1.2. Vector File Formats
1.3. Raster File Formats